qwavfade(1)

NAME
qwavfade - fade in/out wav files

SYNOPSIS
qwavfade [option]... file...

DESCRIPTION

qwavfade modifies a wav file applying on it a fade in or a fade out.

a fade consists in modifying progressively the level of the wav as if you were slowly increasing or decreasing the volume. a fade in consists in increasing the volume starting from a low level at the beginning of the wav. a fade out consists in decreasing the volume to a low level at the end of the wav.

OPTIONS

-d, --duration <duration>[<format>]
    duration is a positive integer that specifies the duration of the fade. the value is treated as a sample number unless a format specifier is used. see the FORMATS section below for information. the default value is five seconds.

-h, --help
    show a brief help and exit.

-i, --in
    just fade in. don't fade out. by default, fade in and fade out.

-o, --out
    just fade out. don't fade in. by default, fade in and fade out.

-t, --test <testfilename>
    testfilename is a string used to name a test file where the fade is applied without modifying the given wav file. this option can be used to test with differents fades before modifying the original wav file. the duration of the test files is the double of the duration of the fade.

-v, --verbose
    show more detailed info.

-V, --version
    show version and exit.

FORMATS

the -d option can have also an optional modifier. if this modifier is not used, then the value provided with the corresponding cut option will be interpreted as a number of samples. since most of the times will be difficult to specify a duration in terms of samples, the following modifiers are provided:

j   value is interpreted as milliseconds.

m   value is interpreted as minutes.

s   value is interpreted as seconds.

b   value is interpreted as bytes.

k   value is interpreted as kbytes (1024 bytes).

M   value is interpreted as megabytes (1024 kbytes).

in either case, the values specified will be rounded to get an integer number of samples.

EXAMPLE
suppose you want to fade in and out the fantastic song live.in.concert.wav using a fade duration of 7 seconds:

first we are going to test:
    qwavfade -t mytest -d 7s live.in.concert.wav

hear the test fades:
    my-favourite-wav-player mytest.fadein.wav
    my-favourite-wav-player mytest.fadeout.wav

if you want to try with another duration, jump to the first step and change the duration argument.

and if you're happy with the tests:
    qwavfade -d 7s live.in.concert.wav

NOTES

the program doesn't allow both types of fades to overlap. if you want to fade in and out a wav file, and the two regions to fade overlap, then probably you made a mistake. in any case, you can do it fading separately.

BUGS

tests has been done only with 44100 Hz 16 bit stereo files, though it may work with mono/stereo 8/16 bits files.

AUTHOR

dmanye@etse.urv.es
http://www.etse.urv.es/~dmanye/quelcom/quelcom.html

SEE ALSO
qwavinfo(1), qwavjoin(1), qwavcut(1), qwavsilence(1), qwavheaderdump(1)
qmp3info(1), qmp3join(1), qmp3cut(1), qmp3check(1), qmp3report(1)